P-nitrodiphenyl ethers

ABSTRACT

NEW COMPOUNDS HAVING THE GENERAL FORMULA FIG-01 WHEREIN R1 REPRESENTS A LOWER ALKYL OR ALLYL RADICAL, R2 REPRESENTS A HYDROGEN OR CHLORINE ATOM OR A METHYL RADICAL, R3 REPRESENTS A HYDROGEN OR CHLORINE ATOM, R2 AND R3 MAY BE IDENTICAL OR DIFFERENT AND N IS 0, 1, OR 2, SAID COMPOUNDS ARE MANUFACTURED BY CONDENSING PHENOL COMPOUNDS HAVING THE GENERAL FORMULA ((R1-S(=O)N-),R2,R3-PHENYL)-O-(1,4-PHENYLENE)-NO2   (WHEREIN R1, R2 AND R3 HAVE THE SAME MEANINGS AS MENKTIONED ABOVE AND N IS 0, 1 OR 2,) WITH P-CHLORONITROBENZENE IN THE PRESENCE OF AN ACID BINDING AGENT. SAID NEW COMPOUNDS HAVE A SELECTIVE AND LASTING HERBICIDAL EFFECT.

United States Patent 6 rm. Cl. C07 c 147/06 US. Cl. 260-607 A 3 Claims ABSTRACT OF THE DISCLOSURE New compounds having the general formula Rs I n R; wherein R represents a lower alkyl or allyl radical, R represents a hydrogen or chlorine atom or a methyl radical, R represents a hydrogen or chlorine atom, R and K, may be identical or different and n is 0, 1 or 2; said compounds are manufactured by condensing phenol compounds having the general formula (wherein R R and R have the same meanings as mentioned above and n is 0, 1 or 2,) with p-chloronitrobenzene in the presence of an acid binding agent. Said new compounds have a selective and lasting herbicidal effect.

DETAILED EXPLANATION OF INVENTION This invention relates to new compounds having the following general formula wherein R represents a lower alkyl or allyl radical, R, represents a hydrogen or chlorine atom or methyl radical, R represents a hydrogen or chlorine atom, and R and R may be identical or different, and n is 0, 1 or 2, and a process for the manufacture thereof.

It has been found that compounds having the above mentioned general formula (I) show an excellent lasting rapid herbicidal effect against fam. Poaceae weeds such as barnyard grass and crab grass as well as broadleaf weeds such as pig weed, and more safety with respect to useful crops and further that undesirable weeds can be prevented selectively for a long time of period by these properties in a paddy field, a field, an orchard, a mulberry field, a turfed area, a pasture etc. while causing no harm to cultivated crops, resulting in the completion of this invention.

ice

Accordingly, the object of this invention is to provide new compounds having an excellent herbicidal effect.

Another object of this invention is to provide a process for the manufacture of such new compounds.

A still further object of this invention is to provide herbicides excellent in the properties of selectivity and lasting.

Effective ingredient compounds (I) tobe used in this invention can be synthesized by the process shown by the following reaction formula:

R2 als(o).oa c1@-No,

R: acid binding agent (II) (III) wherein R R R and n have the same meanings as mentioned above.

The synthesis according to the reaction formula as men tioned above is described as follows: the starting material comprises compounds of the formula (II) and p-chloronitrobenzene, the ratio of the former to the latter being in general between 1.0 and 1.2 times the calculated amount. It is possible however to use a large amount of compound (II) as solvent without using an inert solvent. As acid binding agents, there is used in general sodium or potassium hydroxide in an amount slightly in excess of the calculated amount. When aprotic polar solvents are used as the reaction solvent, potassium carbonate is also an effective acid binding agent.

While the reaction solvent is not absolutely necessary, the use of aprotic polar solvents such as dimethyl sulfoxide, dimethyl formamide, dimethyl acetamide, diethyl ether and diethylene glycol or protic polar solvents such as diethylene glycol monoethyl ether causes the reaction to proceed more smoothly. These solvents may be used not only in any amount as reaction solvent as common sense would indicate, but also in such a small amount as less than ,4 of compound (II) resulting in a best result. The reaction temperature is 200 0., preferably C.

In general, the reaction proceeds smoothly, i.e. more than 95% in 2 hrs., but occasionally it may be necessary to react for about 6 hrs. depending on the reaction conditions or the characteristics of compound (II).

After the reaction, or after the distillation of the solvent after the reaction, the reaction mixture is cooled below 100 0., water is added, the separating oil is extracted with a suitable organic solvent, e.g. benzene, the unreacted compound (II) in the extract is removed by washing with dilute aqueous solution of alkali hydroxide and the solvent is removed by distillation to yield the desired compound (I) in an available purity.

Compounds of the formula (I), wherein n is 0, which are obtained as mentioned above, can be oxidized further by adding an oxidizing agent such as hydrogen peroxide, potassium permanganate or nitric acid to the corresponding sulfoxide or sulfone compounds.

Typical examples of active ingredient compounds in this invention, which are represented by the general formula (I) and obtained in such manner as mentioned above, are given in Table I.

As obviously seen from the Table 2, the active ingredient compounds according to this invention show TABLE 2Continued Active ingredient Weed control Crop injury excellent herbicidal efiects against crab grass (annular D C b P S grass weed) and pig weed (broadleaf grass weed), which Number 1 ig 55 Rice g Remark require a great weeding labor in the crop field cultivation, and on the other hand, there is observed no harm 5 41 33 i8 8 8 against crops such as upland rice andsOybean. 45 50 m 0 O (m) Further, an experimental example 18 given as follows, 100 10 10 0 0 n which the excellent effect as herbicide for field crops 46 50 7 8 0 0 (m) is confirmed by the field test. 10 100 9 9 0 0 4s 50 s 7 0 0 TABLE 2.EFFECTS ON WEEDS AND CROPS 9 3 0 Active ingredient Weed contro Crop injury" 49 38 g g g 8 Number (32 gigs wfe Rice b eg Remark Untreatedcheck 0 0 0 0 1 50 10 1o 0 0 An active ingredient was applied on soil surface as Dre-emergence no effect, 10complete kill. 3 50 10 10 0 0 *Weeds showed albino.

1 EXPERIMENTAL EXAMPLE 2 5 88 ,3 3 8 3 Soil treatment test after seeding in the crop field 1 60 9 9 0 o A given amount of seeds of six plants, i.e. corn, soy- 100 0 0 bean cotton, upland rice and Wheat as the principal field 12 5o 7 9 0 crops and carrot, which requires most labor in weedi g 9 0 0 among vegetables, are sowed in lines and convered with 16 50 0 10 0 0 soil according to a common cultivation. For the c011- firmation of herbicidal effect, a given amount of seeds of 17 50 7 7 0 0 crab grass and pig weed other than spontaneous weeds 9 8 0 0 are mixed uniformly in the surface soil of about 1 cm. is 50 8 7 0 0 thick. Each test section of 1 m? consists of a pair of 100 9 9 0 0 areas and the surface of soil in each section is treated 22 5 7 s 0 o with a liquid reagent diluted with well water at a rate 100 8 9 0 0 of 20 l./a. after sowing so that the amount of active in- 23 50 10 1o 0 0 gredient compound according to this invention ma be 20,

0 0 30, 40, 80 and 120 g./a. respectively. The amount of 26 50 7 10 0 0 remaining weeds and the growth condition of crops are 100 8 0 0 observed in each test section on the twenty fifth day after 29 5o 10 1o 0 o G"); the treatment. The results of observation are given in the 100 0 0 following Table 3.

30 5o 7 9 0 0 0"). As seen in the Table 3, the active ingredient compound 8 0 0 according to this invention is very safe against important 32 50 7 7 0 0 products in the field such as corn, soybean, cotton, upland 100 8 8 0 0 rice, wheat and carrot even in as high amount as 120 33 so 10 10 0 0 g./a. while causing no harm or very little effect. On the 100 0 0 other hand, crab grass and pig weed as main weeds in 34 9 9 0 0 the field as well as almost all annual weeds can be pre- 100 0 vented nearly completely with an amount of reagent less 35 50 9 1o 0 0 than 40 g./a.

9 0 50 While the active ingredient compounds according to this 36 a0 9 10 0 o invention have an excellent effect as herbicide in field 0 0 cultivation as shown in the above Experimental Exam- 37 50 10 10 0 0 pics 1 and 2, the following experimental examples illus- 100 0 0 trate that the compound shows also an excellent effect as 38 50 s 10 o o herbicide in the paddy field and can be used as herbicide 9 0 in many applications.

TABLE 3.-EFFECTS ON UPLAND CROPS AND WEEDS Active ingredient number s 16 2a 29 a3 45 Dose (g./a.)

Plants 20 a0 40 so 120 20 40 so 20 3o 40 so 120 20 so 40 so 120 20 3o 40 so 120 20 so 40 so 120 00120000000000000000000000000o 00o000000000000000000000000000 000100001000010000000001000000 001100000000010000000'00100000o 000000000000000000000000000000 000100001000010001200001000010 Weeds:

Crabgrass 6 7 s 10 10 s 9 10 10 10 s 9 1o 10 10 9 10 10 10 10 s 9 10 10 10 s 10 1o 10 10 0 Pigweed s s 9 10 10 9 9 10 10 10 9 10 10 10 10 9 10 10 10 10 9 10 10 10 1o 9 10 10 10 10 0 Other annual weeds 7 9 10 10 9 9 10 10 10 s 9 1o 10 10 9 10 10 10 10 s 9 i0 10 10 9 10 10 10 10 0 1 Untreated check.

Active ingredient was applied on soil surface as pre-emergence treatment.

Noun-Enact was expressed by the index: 0=no efiect; 10=complete kill.

7 EXPERIMENTAL EXAMPLE 3 A given amount of alluvial paddy field soil is placed in a 1/10,000a pot and adjusted to the final harrowing condition in the common cultivation, a given amount of seeds of barnyard grass is then sowed and stocks of two young paddy rice plants, which are previously cultivated, are planted in the pot. The soil is then irrigated suitably for 7 days to keep it wet, water is added on the seventh day to make the water level 3 cm. deep and 5 ml. of liquid reagent diluted with well water are added dropwise so that the amount of active ingredient compounds according to this invention may be 50 and 100 g./ a. The water level is controlled so as to keep 3 cm. deep during the test. The amount of remaining weeds (barnyard grass) and the growth condition of paddy rice are observed in each test section on the twentieth day after the treatment. The results of observation are given in the Table 4.

TABLE 4.-EFFECTS ON WEED AND CROP Weed contra? Active ingredient Crop mimyq Barnyard grass Dose, with 1 or 1.5 Paddy rice with Number g./a. leaves 4 or 4.5 leaves Untreated check 0 0 *Aetive ingredient was applied in water of paddy field as postemergence treatment.

Seven day old after transplanted.

***Effects were expressed by the index: 0:110 efiect; 10=complete kill.

EXPERIMENTAL EXAMPLE 4 Paddy field; soil incorporation layer before the transplantation of paddy rice A given amount of alluvial paddy field soil is placed in a 1/10,000a pot adjusted to the final harrowing condition, ml. of liquid reagent diluted with well water are added dropwise so that the amount of active ingredient com pound according to this invention may be 50 and 100 g./a. and the surface soil is mixed uniformly up to about 3 cm. deep. A given amount of seeds of barnyard grass is mixed uniformly in the surface soil of about 1 cm. deep and stocks of two young paddy plants, which are previously cultivated, are planted. For the water control during'.the test, the water level is as low as about 0.5 cm. from after the treatment to the beginning of the germination of barnyard grass and the water depth of 3 cm. is kept after the germination. The amount of remaining weeds (barnyard grass) and the growth condition of paddy rice in each test section are observed on the twentieth day after the treatment. The results of observation are given in Table 5.

TABLE 5.-EFFECTS 0N WEED AND CROP Active ingredient Weed control Crop injury.

Transplanted Dos paddy rice with Number g. Barnyard grass 3 or 3.5 leaves Untreated cheek 0 0 Active ingredient was applied as preemergenee treatment in mixing with paddy soil.

kfl121cm.IEiIeets were expressed by the index: 0=no efiect; 10=eomplete As shown in the Experimental Examples 4 and 5, the active ingredient compound according to this invention shows also an'excellent effect as herbicide in the paddy field.

As mentioned above, the herbicides according to this invention can attain sufiiciently the purpose of the invention by using it in an amount of about 15-150 g./a. as active ingredient.

When the active ingredient compounds according to this invention are used as herbicides, it is preferable to use it in admixture with a carrier such as the following: i.e. clay, kaolin, talc, diatomaceous earth, silica, calcium carbonate, sawdust; or benzene, alcohol, acetone, xylene, methyl naphthalene, cyclohexane, dimethyl formamide, dimethyl sulfoxide, animal and vegetable oils, fatty acids, fatty acid esters and various kinds of surface active agents.

Further, auxiliary agents which are used generally in agricultural chemicals, such as one or more extenders, emulsifying, wetting or fixing agents or surface active agents may be added suitably to emphasize or stabilize the effect of active ingredient compounds.

Moreover, the active ingredient compounds or herbicides according to this invention can be used in admixture with other agricultural fungicides, insecticides, nematocides, plant growth controlling agents, soil improving agents or fertilizers.

This invention will be illustrated concretely by the following examples, in which the term part" is shown by weight.

EXAMPLE 1 2-chloro-4-methylsulfonyl-4-nitrodiphenyl ether 3.8 g. (0.018 mole) of 2-chloro-4-methylsulfonyl phenol and 1.1 g. (0.0165 mole) of potassium hydroxide are dissolved completely in 50 ml. of dimethyl formamide with heating. 2.4 g. (0.015 mole) of p-chloro-nitrobenzene is added to the solution and reacted at ISO-140 C. for 3 hrs. with heating.

After the reaction, the resulting mixture is cooled, added to 300 ml. of water and extracted with benzene. The extract is washed with 5% sodium hydroxideand benzene isremoved to yield 4.4 g. (89.7% of theoretical value) of 2- chloro-4-methylsulfonyl-4'-nitrodiphenyl'ether, which can be recrystallized from ethanol M.P 13 2-l134 (3.).

Analysis.Calculated for c ng 'cinogs; 0,4794%; n, 3.08%; N,'4.59%. Found: c, 47.64%; H,.3.08%; N,

9 EXAMPLE 2 3.6 g. (0.055 mole) of potassium hydroxide are dissolved in 20 g. (0.119 mole) of 3-n-propylthio-phenol with heating. 5.8 g. (0.0368 mole) of p-chloronitrobenzene are added to the solution and reacted at l30-140 C. for 4 hrs. with heating. After the reaction, the resulting mixture is cooled, added with 50 ml. of water and extracted with benzene, the extract is washed with 5% sodium hydroxide to remove completely the excess of phenol, and benzene is removed to yield 9.5 g. (89.2% of theoretical value) of crude 3-n propyl-4-nitrodiphenyl ether, which can be re crystallized from ethanol (M.P.: 5253 C.).

Analysis.Calculated for C H NO S: C, 62.25%; H, 5.19%; N, 4.64%.Pound: C, 62.26%; H, 5.22%; N, 4.84%.

EXAMPLE 3 3-n-propylsulfinyl-4-nitrodiphenyl ether 5.0 g. (0.017 mole) of 3-n-propylthio-4'-nitrodiphenyl ether are dissolved in 25 ml. of acetic acid and 2.1 g. (0.0185 mole) of 30% H are added dropwise at -10 C. After the completion of addition, the stirring is continued at room temperature for 2 hrs. to complete the reaction. The resulting mixture is poured on 70 ml. of ice water and extracted with benzene. The extract is washed with 5% aqueous sodium carbonate solution and then with water, dried with anhydrous sodium hydroxide and then benzene is removed under a reduced pressure at above 90 C. of water bath temperature until the weight is constant, to yield the desired 3-n-propylsulfinyl-4'-nitrodiphenyl ether as a viscous brown oil.

Yield: 5.1 g. percent (96.7% of theoretical value):

It may be crystallized from ethanol (M.P.: 50 C.).

Analysis.--Calculated for: C H NO S: C, 57.59%; H, 4.33%; N, 4.62%. Found: C, 57.72%; H, 4.50%; N, 4.81%.

EXAMPLE 4 3-n-propylsulfonyl-4-nitrodiphenyl ether 5.5 g. (0.019 mole) of 3-n-propylthio-4'-nitrodiphenyl ether are dissolved in 30 ml. of acetic acid and 5.2 g. (0.045 mole) of 30% H 0 are added dropwise thereto at 40-50 C. After the completion of addition, the reaction mixture is heated at 90 C. for 1 hr. to complete the reaction. The resulting mixture is cooled and poured into 300 ml. of ice water to crystallize gradually. The crystals are filtered, washed with water sufliciently and dried to yield 5.8 g. (94.7% of theoretical value) of desired 3-npropylsulfonyl-4'-nitrodiphenyl ether, which can be recrystallized from ethanol (M.P.: 101-102 C.).

Analysis-Calculated for C H NO S: C, 56.02%; H, 4.69%; N, 4.17%. Found: C, 56.06%; H, 4.71%; N, 4.36%.

EXAMPLE 5 parts of 4-methylsulfonyl-4'-nitrodiphenyl ether are mixed with 45 parts of talc and 45 parts of clay and ground to yield a powder agent, which is scattered as it is for use.

EXAMPLE 6 20 parts of 2-chloro-4-methylthio-4'-nitrodiphenyl ether are mixed with 60 parts of kaolin and 17 parts of dia- 10 tomaceous earth and then with 1 part of alkyl naphthalene sulfonic acid salt and 2 parts of ligninsulfonic acid salt and ground to form a hydrating agent, which is suspended in water to use as liquid sprinkle.

EXAMPLE 7 20 parts of 3-n-propylthio-4'-nitrodiphenyl ether are dissolved in 63 parts of xylene and mixed with 17 parts of alkyl phenol-ethylene oxide condensate to yield an emulsion, which is diluted with water to use as emulsion.

EXAMPLE 8 One part of polyoxyethylene alkyl ether is applied uniformly to the surfaces of 92 parts of lime stone particles having a particle size of 0.3-0.1 mm. and mixed with 7 parts of finely divided 2-chloro-4-methylsul-finyl-4'-nitrodiphenyl ether to coat the particles resulting in fine granules, which are scattered by hands or a scattering machine as they are.

EXAMPLE 9 wherein R represents a lower alkyl or allyl radical, R represents a hydrogen or chlorine atom or a methyl radical, R represents a hydrogen or chlorine atom, and 1R and R may be identical or difierent, and n is 1 or 2. 2. Compounds according to claim 1, wherein the radical is at the mor p-position of the phenyl radical. 3. Compounds according to claim 2, wherein the radical is at the m-position of the phenyl radical.

Iii-5(0) References Cited FOREIGN PATENTS 1,173,278 12/1969 Great Britain 260-607 A 1,930,256 12/1970 Germany 260607 A OTHER REFERENCES Chem. Abstracts, 18647A, Vol. 1960.

LEWIS GOTTS, Primary Examiner D. R. PHILLIPS, Assistant Examiner US. Cl. X.R. 

